Effects of a Knee Extension Constraint Brace on Selected Lower Extremity Motion Patterns during a Stop-Jump Task

in Journal of Applied Biomechanics
View More View Less
  • 1 University of North Carolina at Chapel Hill
  • 2 Beijing University of Sports
  • 3 Duke University Medical Center
Restricted access

Purchase article

USD  $24.95

Student 1 year online subscription

USD  $88.00

1 year online subscription

USD  $118.00

Student 2 year online subscription

USD  $168.00

2 year online subscription

USD  $224.00

Small knee flexion angle during landing has been proposed as a potential risk factor for sustaining noncontact ACL injury. A brace that promotes increased knee flexion and decreased posterior ground reaction force during landing may prove to be advantageous for developing prevention strategies. Forty male and forty female recreational athletes were recruited. Three-dimensional videographic and ground reaction force data in a stop-jump task were collected in three conditions. Knee flexion angle at peak posterior ground reaction force, peak posterior ground reaction force, the horizontal velocity of approach run, the vertical velocity at takeoff, and the knee flexion angle at takeoff were compared among conditions: knee extension constraint brace, nonconstraint brace, and no brace. The knee extension constraint brace significantly increased knee flexion angle at peak posterior ground reaction force. Both knee extension constraint brace and nonconstraint brace significantly decreased peak posterior ground reaction force during landing. The brace and knee extension constraint did not significantly affect the horizontal velocity of approach run, the vertical velocity at takeoff, and the knee flexion angle at takeoff. A knee extension constraint brace exhibits the ability to modify the knee flexion angle at peak posterior ground reaction force and peak posterior ground reaction force during landing.

Lin and Yu are with the Center for Human Movement Science, Division of Physical Therapy, University of North Carolina, Chapel Hill, NC; Liu is with the Sports Biomechanics Laboratory, College of Sports Human Movement Science, Beijing Sports University, Beijing, China; and Garrett is with the Duke Sports Medicine Center, Duke University Medical Center, Durham, NC.